1. Field of the Invention
This invention relates to methods and apparatus for performing microanalytic and microsynthetic analyses and procedures. In particular, the invention relates to microminiaturization of genetic, biochemical and chemical processes related to analysis, synthesis and purification. Specifically, the invention provides a microsystem platform and a micromanipulation device to manipulate the platform by rotation, thereby utilizing the centripetal forces resulting from rotation of the platform to motivate fluid movement through microchannels embedded in the microplatform. The microsystem platforms of the invention are also provided optionally having system informatics and data acquisition, analysis and storage and retrieval informatics encoded on the surface of the disk opposite to the surface containing the fluidic components. Methods for performing any of a wide variety of microanalytical or microsynthetic processes using the microsystems apparatus of the invention are also provided.
2. Background of the Related Art
In the field of medical, biological and chemical assays, a mechanical and automated fluid handling systems and instruments produced to operate on a macroscopic (i.e., milliliters and milligrams) scale are known in the prior art.
U.S. Pat. No. 4,279,862, issued Jul. 21, 1981 to Bertaudiere et al. disclose a centrifugal photometric analyzer.
U.S. Pat. No. 4,381,291, issued Apr. 26, 1983 to Ekins teach analytic measurement of free ligands.
U.S. Pat. No. 4,515,889, issued May 7, 1985 to Klose et al. teach automated mixing and incubating reagents to perform analytical determinations.
U.S. Pat. No. 4,676,952, issued Jun. 30, 1987 to Edelmann et al teach a photometric analysis apparatus.
U.S. Pat. No. 4,745,072, issued May 17, 1988 to Ekins discloses immunoassay in biological fluids.
U.S. Pat. No. 5,160,702 issued Nov. 3, 1992 to Kopf-Sill et al. discloses a centrifuge rotor for analyzing solids in a liquid.
U.S. Pat. No. 5,171,695, issued Dec. 15, 1992 to Ekins discloses determination of analyte concentration using two labeling markers.
U.S. Pat. No. 5,173,262 issued Dec. 22, 1996 to Burtis et al. discloses a centrifuge rotor for processing liquids.
U.S. Pat. No. 5,242,803, issued Sep. 7, 1993 to Burtis et al. disclose a rotor assembly for carrying out an assay.
U.S. Pat. No. 5,409,665, issued Apr. 25, 1995 to Burd disclose cuvette filling in a centrifuge rotor.
U.S. Pat. No. 5,413,732, issued May 9, 1995 to Buhl et al. teach preparation of lyophilized reagent spheres for use in automated centrifugal blood analyzers.
U.S. Pat. No. 5,432,009, issued Jul. 11, 1995 to Ekins discloses a method for analyzing analytes in a liquid.
U.S. Pat. No. 5,472,603 issued Dec. 5, 1995 to Schembri discloses an analytical rotor for performing fluid separations.
Anderson, 1968, Anal Biochem. 28: 545-562 teach a multiple cuvette rotor for cell fractionation.
Renoe et al., Clin. Chem. 20: 955-960 teach a xe2x80x9cminidiscxe2x80x9d module for a centrifugal analyzer.
Burtis et al., Clin. Chem. 20: 932-941 teach a method for dynamic introduction of liquids into a centrifugal analyzer.
Fritsche et al. 1975, Clin. Biochem. 8: 240-246 teach enzymatic analysis of blood sugar levels using a centrifugal analyzer.
Burtis et al., Clin. Chem. 21: 1225-1233 a multipurpose optical system for use with a centrifugal analyzer.
Hadjiioannou et al. 1976, Clin. Chem. 22: 802-805 teach automated enzymatic ethanol determination in biological fluids using a miniature centrifugal analyzer.
Lee et al., 1978, Clin. Chem. 24: 1361-1365 teach an automated blood fractionation system.
Cho et al., 1982, Clin. Chem. 28: 1961-1965 teach a multichannel electrochemical centrifugal analyzer.
Bertrand et al., 1982, Clinica Chimica Acta 119: 275-284 teach automated determination of serum 5xe2x80x2-nucleotidase using a centrifugal analyzer.
Schembri et al., 1992, Clin. Chem. 38: 1665-1670 teach a portable whole blood analyzer.
Walters et al., 1995, Basic Medical Laboratory Technologies, 3rd ed., Delmar Publishers: Boston teach a variety of automated medical laboratory analytic techniques.
Recently, microanalytical devices for performing select reaction pathways have been developed.
U.S. Pat. No. 5,006,749, issued Apr. 9, 1991 to White disclose methods and apparatus for using ultrasonic energy to move microminiature elements.
U.S. Pat. No. 5,252,294, issued Oct. 12, 1993 to Kroy et al. teach a micromechanical structure for performing certain chemical microanalyses.
U.S. Pat. No. 5,304,487, issued Apr. 19, 1994 to Wilding et al. teach fluid handling on microscale analytical devices.
U.S. Pat. No. 5,368,704 issued Nov. 29, 1994 to Madou et al. teach microelectrochemical valves.
International Application, Publication No. WO93/22053, published Nov. 11, 1993 to University of Pennsylvania disclose microfabricated detection structures.
International Application, Publication No. WO93/22058, published Nov. 11, 1993 to University of Pennsylvania disclose microfabricated structures for performing polynucleotide amplification.
Columbus et al, 1987, Clin. Chem. 33: 1531-1537 teach fluid management of biological fluids.
Ekins et al., 1992, Ann. Biol. Clin. 50: 337-353 teach a multianalytical microspot immunoassay.
Wilding et al., 1994, Clin. Chem. 40: 43-47 disclose manipulation of fluids on straight channels micromachined into silicon.
The prior art discloses synthetic microchips for performing microanalytic and microsynthetic methods. One drawback in the prior art microanalytical methods and apparati has been the difficulty in designing systems for moving fluids on the microchips through channels and reservoirs having diameters in the 10-100 xcexcm range. Also, the devices disclosed in the prior art have required separate data analysis and storage media to be integrated into an instrument for performing the microanalysis, thereby unnecessarily increasing the complexity of the instruments designed to use the microchips, without a concomitant increase in the flexibility or usefulness of these machines.
There remains a need for a simple, flexible, reliable, rapid and economical microanalytic and microsynthetic reaction platform for performing biological, biochemical and chemical analyses and syntheses that can move fluids within the structural components of a microsystems platform. Such a platform should be able to move nanoliter to microliter amounts of fluid, including reagents and reactants, at rapid rates to effect the proper mixing of reaction components, removal of reaction side products, and isolation of desired reaction products and intermediates. There is also a need for an instrument for manipulating the microsystem platform to effect fluid movement, thermal control, reagent mixing, reactant detection, data acquisition, data analysis and data and systems interface with a user. Such devices are needed, in alternative embodiments, that are sophisticated (for professional, e.g., hospital, use), easy to use (for consumer, e.g., at-home monitoring, uses) and portable (for field, e.g., environmental testing, use). Such devices also advantageously combine xe2x80x9cwetxe2x80x9d chemistry capabilities with information processing, storing and manipulating ability.
This invention provides an integrated, microanalytical/microsynthetic system for performing a wide variety of biological, biochemical and chemical analyses on a microminiature scale. The invention provides apparatus and methods for performing such microscale processes on a microplatform, whereby fluid is moved on the platform in defined channels motivated by centripetal force arising from rotation of the platform.
In one aspect of the invention is provided a microanalytic/microsynthetic system comprising a combination of two elements. The first element is a microplatform that is a rotatable structure, most preferably a disk, the disk comprising sample, inlet ports, fluid microchannels, reagent reservoirs, reaction chambers, detection chambers and sample outlet ports. The disk is rotated at speeds from about 1-30,000 rpm for generating centripetal acceleration that enables fluid movement. The disks of the invention also preferably comprise fluid inlet ports, air outlet ports and air displacement channels. The fluid inlet ports allow samples to enter the disk for processing and/or analysis. The air outlet ports and in particular the air displacement ports provide a means for fluids to displace air, thus ensuring uninhibited movement of fluids on the disk. Specific sites on the disk also preferably comprise elements that allow fluids to be analyzed, including thermal sources, light, particularly monochromatic light, sources, and acoustic sources, as well as detectors for each of these effectors. Alternatively, some or all of these elements can be contained on a second disk that is placed in optical or direct physical contact with the first.
The second element of the invention is a micromanipulation device that is a disk player/reader device that controls the function of the disk. This device comprises mechanisms and motors that enable the disk to be loaded and spun. In addition, the device provides means for a user to operate the Microsystems in the disk and access and analyze data, preferably using a keypad and computer display.
The invention provides methods and apparatus for the manipulation of samples consisting of fluids, cells and/or particles containing or comprising an analyte. The microplatform disks of the invention comprise Microsystems composed of, but no restricted to, sample input ports, microchannels, chambers, valves, heaters, chillers, electrophoretic and detection systems upon a disk. Movement of the sample is facilitated by the judicious incorporation of air holes and air displacement channels that allow air to be displaced but prevent fluid and/or particle loss upon acceleration.
A preferred embodiment of the disk of the invention incorporates micromachined mechanical, optical, and fluidic control structures (or xe2x80x9csystemsxe2x80x9d) on a substrate that is preferably made from plastic, silica, quartz, metal or ceramic. These structures are constructed on a sub-millimeter scale by photolithography, etching, stamping or other appropriate means.
Sample movement is controlled by centripetal or linear acceleration and the selective activation of valves on the disk.
In preferred embodiments of the invention, a section of the disk is dedicated to information processing by standard read/write digital technology. Data resulting from processing and analysis is recorded on the disk surface using digital recording means. In additional preferred embodiments, read-only memory (ROM) on the disk comprises disk information, instructions, experimental protocols, data analysis and statistical methods that can be accessed by a user operating the disk.
The process of fluid transport by centripetal acceleration and the micromanipulation device that enables such processing have a wide range of applications in the synthesis and analysis of fluids and detection of analytes comprising a fluid, particularly a biological fluid. Chemical and biochemical reactions are performed in a reaction chamber on the disk by the selective opening of contiguous reagent chambers by means of capillary, mechanical or thermal valve mechanisms. The contents of those chambers are delivered to the reaction chamber with the application of centripetal acceleration. The product of the reaction can then be used as a reagent for subsequent reactions, interrogated by detection systems or recovered.
Certain preferred embodiments of the apparatus of the invention are described in greater detail in the following sections of this application and in the drawings.